Effect of healthy lifestyle score trajectory on all-cause mortality in the late middle-aged and older population: Finding from 17-year retrospective cohort study

Recently, the World Health Organization has emphasized the importance of a healthy lifestyle in reducing severe illnesses and premature mortality. To evaluate this, the Healthy Lifestyle Score (HLS), which focuses on health protecting behaviors (e.g., smoking, alcohol consumption, physical activity, body mass index), is widely used. However, as HLS may fluctuate over time, there is increasing focus on monitoring HLS trends. Accordingly, this study aims to track HLS trajectories (HLST) and examine their association with mortality among middle-aged and older Koreans. After excluding missing values, data from 6249 participants were analyzed using the group-based trajectory model (GBTM) to classify HLST, based on the first to fourth waves of the Korean Longitudinal Study of Aging (KLoSA). The chi-square test and Cox proportional hazards model were employed to examine the association between HLST and all-cause mortality over a 10-year follow-up period (December 31, 2012, to December 31, 2022; 3650 days). Three HLST groups were identified in the GBTM analysis. These were the Poor HLST (17.8 %), Average HLST (42.9 %), and Good HLST (39.4 %) groups. Compared to the good HLST, the poor HLST had higher mortality at 1 year (hazard ratio [HR]: 1.98, p: 0.029), 3 years (HR: 1.78, p: 0.001), 5 years (HR: 1.52, p: 0.002), 7 years (HR: 1.39, p: 0.002), and 10 years (HR: 1.40, p: 0.000). Furthermore, stratified analysis by sex, age, marital status and residential region showed that male, ≥65 years, single and urban area groups had a strong association between HLST and all-cause mortality. The findings of this study underscore the necessity of policies and institutional measures grounded in community networks to mitigate the risk of all-cause mortality among vulnerable groups with persistently poor HLST.